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Topic Title: L.E.D. Floodlight Failure and
Topic Summary: Fusing.
Created On: 23 September 2017 11:33 AM
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 23 September 2017 11:33 AM
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Zoomup

Posts: 3430
Joined: 20 February 2014

Mornin All,
I was called out to a lighting failure. The upstairs lights in a large house caused the 6 Amp. M.C.B. to trip off and it would not reset.

After removing all lamps and carrying out insulation resistance testing the fault was located on an external L.E.D. floodlight. The L to N resistance was about 4 Ohms.

Why don't these type of fittings have an internal fuse or other device to disconnect just them if they short circuit? The light was at high level and was not easy to access. It did not have a local or even a remote isolator so that the householder could operate it and disconnect it. Local or internal fusing would prevent inconvenience.

What are others' views.

Bye,

Z.
 23 September 2017 11:39 AM
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broadgage

Posts: 2450
Joined: 07 August 2007

Adding an internal fuse would add at least a penny to the manufacturing cost, and probably as much as ten pence to the UK retail price.
IME these lights are generally chosen on the basis of least first cost.
 23 September 2017 11:51 AM
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dustydazzler

Posts: 1504
Joined: 19 January 2016

The last light fitting I installed that had a tiny internal glass fuse I managed to blow the fuse doing an efli test on that circuit.
Spent the rest of the day trying to source a replacement glass fuse.
Eventually had to buy a pack of 10 off fleabay
 23 September 2017 01:18 PM
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weirdbeard

Posts: 3116
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On the bright side, the fixed installation protection has worked as intended and is preventing the re-energising of a fault despite being bang tested at least once, and being a big house probably plenty more things that need improving

-------------------------
:beer)
 23 September 2017 04:34 PM
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Legh

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After removing all lamps and carrying out insulation resistance testing the fault was located on an external L.E.D. floodlight. The L to N resistance was about 4 Ohms.


A client of mine had the same problem. They had to remove 14 garden LED spike lamps and replace each one and test until they found the culprit.
Someone will eventually need to design LED lamps to fail in open circuit mode....

Legh

-------------------------

http://www.leghrichardson.co.uk

de-avatared
 24 September 2017 09:23 PM
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KFH

Posts: 566
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I also have had problems with faulty LED lamps of various makes failing long before their quoted lifetime, fortunately always open circuit. The ones that fail are always the ones in the most inaccessible positions, the most distant customers or both. Usually within a year of installation so I have the opportunity to replace them free of charge.

I wonder with all the advances of technology if we will ever get reliable lights?
 24 September 2017 11:24 PM
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MWalker86

Posts: 99
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Originally posted by: Zoomup

Why don't these type of fittings have an internal fuse or other device to disconnect just them if they short circuit? The light was at high level and was not easy to access. It did not have a local or even a remote isolator so that the householder could operate it and disconnect it. Local or internal fusing would prevent inconvenience.

Z.


A decent quality driver will have short-circuit protection and refuse to operate, this won't be as simple as a fuse, it will be built into it's circuitry/firmware. Granted this is only on the load side so doesn't prevent any problems between terminal blocks and the driver, but still it's half the battle.

The main problem with LED luminaires on the market today is that they are actually quite sophisticated little things to do RIGHT. It's very easy for wun hung lo in shanghai to knock something out for a few dollars that yes, technically is an led fitting and yes still will produce some good energy savings, but.... it will break in five minutes.

But 90% of customers will only look at the price and not any respectable guarantee of quality, because (as I initially thought too) "Well a lights a light, what's so complicated?"

They don't really understand just what a leap it is from hot wire in a glass to making light by messing with electron energy states across slightly differing materials.

As a UK manufacturer we produce thousands of luminaires a day and the rectification engineers very very rarely have to go out fix a short.
 25 September 2017 12:12 AM
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kellyselectric

Posts: 191
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Ha LEDisese strikes again a perfect example of why I would NEVER give these horrible things houseroom. I hate them with a passion. Its another example of manufacturer's failing to meet minimum standards I would of thought local fusing would be a minimum requerment

Edited: 25 September 2017 at 12:28 AM by kellyselectric
 25 September 2017 10:52 PM
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MWalker86

Posts: 99
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Originally posted by: kellyselectric

Ha LEDisese strikes again a perfect example of why I would NEVER give these horrible things houseroom. I hate them with a passion. Its another example of manufacturer's failing to meet minimum standards I would of thought local fusing would be a minimum requerment


Well you're gonna be outta luck pretty soon. The fluorescent side of the market is shrinking by the day. It's now statistically unusual for us to sell one.

Local fusing is only a requirement for emergency luminaires according to 60598-2-22 (it's actually not specified as a fuse, it's just worded in such a way that noone in their right mind would do anything but bang a fuse in).

Would you mind expanding on why you dislike LED with such passion?
 25 September 2017 11:16 PM
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kellyselectric

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I actually have a very large collection of filament lamps that I squerelled away over the last few years so I'm good for a while yet. I dislike LEDisease so much because they give an awful harsh white light although il concede that some of them do give a realistic filament glow now. The second reason is that very often there is a noticable 100 cycle flicker which is very iritating. Third reason and this is kind of personal is that the only 2 eco friendly types ive ever met were so nasty and vitriolic with there opinions they virtualy shouted me down ( made me cry) and ive never met such nastiness so I just completely go against whatever they say now. 4th its something thats been forced on us and I thought the UK was meant to be a democracy. Ok thats me done I'm put my soap box away now
 25 September 2017 11:25 PM
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mapj1

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I don't know for sure why he does not like them, suspect reliability, or more lack of it, but personally as an electronics and RF man, I despair at the utterly atrocious EMC performance, of both CFL, and many of the newer LED devices.
By this I mean mainly in terms of conducted and radiated emissions, Not even making the fairly easy limits needed for CE marking. (that in IEC60950, EN55022) (my background would expect DefStan or Mil STD. ) but in my home case, immunity as well. At least the iron ballasted florrys only light up with the transmitter on, while the LED drivers die and have the temerity to fail S/C and to take the MCB with them. And don't even mention PIR activated devices and a few tens of volts per metre of HF.
It is of course possible to do properly, but domestic fitting design seems to be very much a race to the bottom, not even meeting the basic EN requirements. In that sense for the lower wattages the capacitor dropper plus diode bridge has much to recommend it, or the 12V DC led strings and a linear supply or battery, by having so little active electronics to be cocked up. Luckily for me there are still plenty of filament lamps about, or one day I will have to build my own.

edit OK we cross posted. His reasons are not mine.
pages 8 and 9 of this EU survey make depressing reading the fractions that comply with the standards.

-------------------------
regards Mike


Edited: 25 September 2017 at 11:32 PM by mapj1
 26 September 2017 12:45 AM
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kellyselectric

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Should reason HER reasons I'm a girl!
 26 September 2017 01:28 PM
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mapj1

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Please accept my apologies.
I'm afraid it is hard to tell from the name, and I had assumed 'Kelly' was a surname.

(I'm a bloke by the way ...)

-------------------------
regards Mike
 26 September 2017 05:55 PM
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kellyselectric

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Lol ok not to worry if your interested my first names are Kelly Jayne so now you know
 26 September 2017 11:54 PM
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mapj1

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Ah well. Now, such errors of assumption do occur. As an example of the earliest involving me, my mother had been planning on calling me Suzanne Elizabeth while she was expecting me.
However, after the delivery of the mk1 MAPJ1, the plans had to be rapidly updated in the light of new information, not un-like some projects I've worked on over the years..

-------------------------
regards Mike
 27 September 2017 01:42 AM
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MWalker86

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At the risk of sounding like a broken record, all these objections to LED only apply in the cheap end of the market.
 27 September 2017 09:33 AM
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Zoomup

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The thing is, that we just do not know about the good design or reliability of a L.E.D. luminaire until it has been in use for a period of time in most cases. They all look the same. How do we know that the more expensive one is better than an economy version? That is just an assumption until proof is available.

Z.
 27 September 2017 09:34 AM
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KFH

Posts: 566
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Originally posted by: MWalker86

At the risk of sounding like a broken record, all these objections to LED only apply in the cheap end of the market.


Yes and no. I have fewer failures with the expensive stuff but I have still had them. I have put in some really cheap stuff, in my own house in an easy to access position, they have lasted very well.

I have also had about 30% failure rate during the first 6 months on a large house installation. By the time I could get access to the house, the customer was on an extended holiday, the supplier, one of the well known internet suppliers at the cheaper end, could not supply a replacement bulb with the same or similar colour temp, lumens output, lighting angle or appearance when off. I had to mess around moving bulbs around so they had a similar appearance in each room.

I have had 100% failure rate with some makes as I have only installed one of their external lights before going for an alternative make, I did manage 200% failure rate with one manufacturer, not the cheapest, when the replacement I reluctantly accepted was also faulty. the wholesalers nearly always say "that is the first one we have had to replace"

I am now reluctant to fit any LED fitting where I cannot replace the bulb and would prefer not to fit them at all. Having just about retired I am fortunate that I don't now have to. For home use I buy the cheaper ones and a few spares on the basis I will replace them when they fail.

While LEDs save electricity in my experience the amount of diesel I have wasted replacing them outweighs any benefit.
 28 September 2017 10:01 AM
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mapj1

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MWalker86 Posts: 94 Joined: 05 June 2017 At the risk of sounding like a broken record, all these objections to LED only apply in the cheap end of the market.



That maybe at the level of wholesale price. By it reaches the customer the cheaply built stuff is still sold at full price sometimes.
Personally what I see as needed is for the (few) good manufacturers to make it a selling point, like Volvo cars and safety in the '70s
Publish the EMC results, the FIT analysis, offer a lifetime garuantee that can be claimed on - even perhaps publish a " why we cost more" tear down of some of the opposition, liek the car crashes of the other makers.

-------------------------
regards Mike
 28 September 2017 02:20 PM
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ArduinoXR

Posts: 58
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Originally posted by: kellyselectric

Ha LEDisese strikes again a perfect example of why I would NEVER give these horrible things houseroom. I hate them with a passion. Its another example of manufacturer's failing to meet minimum standards I would of thought local fusing would be a minimum requerment


Once they have been ENEC+ tested they shouldn't prove any trouble. Sounds like you've just had a few bad experiences. LED technology is improving every day.
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